Preheat the oven to 400 degrees F.

Beat two large eggs in a bowl and set aside. In a large plastic bag add the fish breading and set aside.

Slice the ends of the onions and discard. Remove the outer layer and discard.
Slice the onions into thick slices. Carefully separate all of the onion rings.

Use a fork and dip the onion slices into the egg, being sure to fully submerge and coat well. Toss the onions into the fish breading and be sure it is coated completely.

Place the onion rings on a baking sheet, be sure the rings do not touch, or they will not get crisp. This will likely take two large baking sheets.

Spray the onions well with cooking oil (This is key! Do not skip!)

Bake the onion rings 10-12 minutes until they are golden on the bottom, flip and bake an additional 5-6 minutes or until they are crispy.

Please remember cooking times will depend on how thickly you sliced your onions and how crowded your pan is. Remove the onions from the oven when they are golden brown and crispy.